about dc ckt. ground

[shrinivasdevkar]

I am facing problem during combining two dc ckts. one of them is 5V dc power supply with IC324 quard op-amp and other is a one selec temperature controller device TC303 AX.

when i combine two ckt. GND. the voltage changes from 5V to 0.35V how???

 

[Harald Kapp]

You can bet that there is another connection between the circuits somewhere. By connecting the grounds you create a (almost) short circuit. I'm sure if you use an ammeter to connectthe grounds you will observe a large current flowing. This is what lets the supply voltage break down.

Find all curent paths between the circuits and eliminitae the one that is responsible forthe short circuit.

 

[shrinivasdevkar]

i.e. we can short ground of two dc ckts. for combining them

 

[gorgon]

If you are feeding both circuits from the same power supply, and the Power short circuit when connecting the GND of both circuits, it could indicate that GND for one circuit is +Vcc for the other. Or something else is not connected correct.

 

[shrinivasdevkar]

Sir as i told you iwant make two dc ckt combine these two ckts are as follows..........one ckt has 230V50Hz supply from that i'm taking 5.625V supply developed inthat device itself and for other we developed power supply unit of 5V .....

 

[gorgon]

The photos doesn't tell too much. Could you please post a schematics of the two circuits?